Pharmacology and the Aged Flashcards
Those over the age of 65 make up what percentage of all prescriptions
30-35%
Avg number of meds for someone in LTF
8
Drug
Substance that alters cell function
Side effect
Unwanted effects of drug
Effect
Action of drug
What the drug does
Adverse drug reaction
Undesirable or unwanted effect of drug
Compliance
Taking drug as directed
Pharmacodynamics
Study of affect of drugs at the target site (usually receptor)
Pharmacokinetics
Study of time course of drug and metabolite levels in body fluids during absoprtion, distribuion, metablism, and elimination of drug
Polypharmacy
Taking a number of drug
How do normal age changes affect pharmacology
Altered drug deposition and metabolism Dec lean body mass Inc body fat Reduction in liver function Dec in proteins in blood stream Altered absorption Reduces stomach acid Reduces GI motility
Altered Drug disposition and metabolism
Dec body weight Dec lean body mass Inc body fat Dec total body water Dec plasma albumin Redstribution of regional blood flow
Dec lean body mass - effect
There are fewer cells per unit of body weigth
Dec lean body mass - importance
Drug dosages calculated on presumption of X number of cells per unit of body weigth
Dec lean body mass - consequences
More drug per cell - more side effects, more toxicity, overdose
Need to recalculate dose for older adultd
Significance of inc body fat
Larger volume for fat soluble drugs to distribute
Prolongs duration of some drugs
Liver function - aging dec
The number of liver cells
Blood flow to the liver
Enzymes to break down drug
COnsequences of liver function change
Drugs remain active for longer period of time
Inc drug concentration in blood
Role of proteins
Bind and serve as a store
Prevent drug from being metabolized
Concentration of proteins in aged adult
dec 15-25%
Consequences of changes in proteins in blood stream
More free drug leads to more activity
Concern of dec proteins in blood
Illness and poor nutrition will worse problem
Altered absorption
Inc gastric pH Dec splanchnic blood flow Dec GI mobility Delayed gastric emptying Altered active transport
Consequences of dec stomach acid
Reduced bioavailability of some tablets/capsules
Absoprtion of some drugs requires acid media
Altered rate of stomach emptying
Reduced drug absoprtion
Consequences of reduction in GI motility
Less mixing of contents
Less exposing the drug to intestinal wall for absorption
Net effect of reduction in GI motility
Delayed absoprtion
Irritating drugs do more damage
Adverse drug reaction
Any undesirable or unintended drug effect
Includes side effects
Toxicity
Allergic reaction
Classification of types of ADRs
ABCDE Augmented drug effects Bizarre effects Chronic effects Delayed effects End ot tx effects
Augmented drug effects
Dose related effects of drug
Bleeding due to anticoagulants
Bizarre effects
Uncommon, unpredictable effects
Anaphylaxis due to penicillin
Chronic effecs
Due to prolonged treatment (many doses)
Colic dysfunction due to laxatives
Delayed effects
Adverse effect not related to initial reason for drug
Second type of cancers after therapy for initial cancer
End of tx effects
Effects occur when drug is stopped
Causes of drug toxicity in older adults - provider causes
Duplication of medications
Imprecise directions
Poor drug history
Causes of drug toxicity in older adults - patient causes
Poor self selection of OTC drugs Poor drug hx Sensory and mental deficits Drug induced confusion Lack of knowledge drugs/effects/aging
Causes of drug toxicity in older adults - pharmacy causes
Automatic refills
Error
No medication/interaction profile
Guidelines for safety with medications for older adults
Make sure they know the meds they are on
Make sure they are taking prescribed amount
Refer on if you or pt recognizes side effects
Encourage pt to see pharmacist to review meds
Causes for lack of compliance
Inability to afford Inability to adhere to complicated regimen Cognitive, funct, sens impairment Lack of knowldege Denial of illness Unclear instructions Inappropriate dosage form Feel better without med Use of alcohol
Compliance aids
Calendars Charts Blister packs Pill boxes Programmable alarm devices Caregiver training Home health aides
